The chemical structure of SRS-A's (slow reacting substances of anaphylaxis) has been recently reported to be thioaminoacid-containing polyunsaturated fatty acids, namely, 5-hydroxy-6-cysteinylglycinyl-7,9,11,14-eicosatetraenoic acid (leukotriene D, LTD.sub.4); 5-hydroxy-6-cysteinyl-7,9,11,14-eicosatetraenoic acid (LTE.sub.4); and 5-hydroxy-6-glutathionyl-7,9,11,14-eicosatetraenoic acid (LTC.sub.4). These leukotrienes are believed to be the products of arachidonic acid metabolism through the lipoxygenase biosynthetic pathway. Leukotrienes are thought to be potent spasmogens produced or released in allergic diseases. This invention includes compounds, related to the natural leukotrienes, which have been demonstrated to exhibit antiallergic properties and also pharmaceutical compounds and processes for their use as antiallergens.